Income Taxes (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($) item	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Income Taxes
Effective income tax rate (as a percent)	31.80%	26.10%	31.20%	27.50%
Reversal of previously unrecognized tax benefits due to lapsing of statute of limitations (as a percent)	0.60%	5.30%	0.50%
Unfavorable impact of foreign currency exchange on tax provision (as a percent)	5.40%		3.00%
Provision for (reversal of) income taxes	$ 51.2	$ 42.6	$ 138.3	$ 113.9
Percentage points that relates to audit result related to a pre-acquisition period	(2.40%)		(0.90%)
Effective income tax rate excluding significant adjustments (as a percent)	29.00%	28.00%	29.00%	28.00%
Number of discrete tax adjustments | item		2
Akzo Nobel NV
Income Taxes
Provision for (reversal of) income taxes	$ (4.0)	$ 7.0
Percentage points that relates to audit result related to a pre-acquisition period		4.50%
Other income		$ 7.0
Impact of pre-acquisition adjustment on net income		$ 0.0